Penguin-Inspired Propulsor (1 of 2) (IMAGE) American Institute of Physics Caption This actuated spherical joint mimics a penguin shoulder while enabling compactness, rigidity and high motion frequencies, as well as unlimited rotation (propeller-like, not shown on the video) about a single shaft. Credit hepia/B.Sudki-M.Lauria-F.Noca Usage Restrictions This image may be used only with appropriate caption and credit. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.